Electronic flash unit



FIG. 1 is a perspective view of the electronic flash unit showing my new design;

FIG. 2 is a front elevational view;

FIG. 3 is a rear elevational view;

FIG. 4 is a right side elevational view;

FIG. 5 is a left side elevational view;

FIG. 6 is a top plan view;

FIG. 7 is a bottom plan view. 

The ornamental design for an electronic flash unit, as shown. 